Apparent Digestibility of Phosphorus in Barley and Corn for Growing Swine

Abstract

Two experiments involving a total of 26 pigs were conducted to determine the apparent digestibility of the phosphorus in barley and corn for growing swine. Diets were calculated to contain all known nutrients, except phosphorus, at requirement levels. Each animal completed two 5-day digestion trials during which they were fed twice daily. In experiment I, the apparent digestibility of phosphorus from dicalcium phosphate in the corn grits control diets was calculated to be 66.3 and 62.7% for the .3 and .5% total phosphorus levels, respectively. Using these values to extrapolate the phosphorus excretion from dicalcium phosphorus in the barley diets, apparent phosphorus digestibility of barley was calculated to be 16.5 and 41.3% for the .3 and .5% phosphorus levels, respectively. In experiment II, when pigs were fed diets containing .3% total phosphorus, apparent phosphorus digestibility of corn was 8.3% as compared to 64.8% digestible phosphorus of dicalcium phosphate.